1. Field of the Invention
The present invention relates to a method for printing a stereograph and a related printing device, and more particularly, to a method for manufacturing a lenticular lens structure on a protecting region of a ribbon so as to print a stereograph and a related printing device.
2. Description of the Prior Art
A stereograph can transfer a viewer's view angle from two-dimensional space into three-dimensional space, so as to restore a scene with depth of field on the stereograph and to improve a sense of reality of the scene. Thus, the viewer can distinguish a distance and a depth of the scene on the stereograph. Method for producing three-dimensional vision utilizes parallax theory, such as adjusting radian of eyes for changing focal lengths of the eyes and adjusting view angles of the eyes. Because the stereograph shows images having different angles and distances on two eyes of the viewer, respectively, parallax is generated between the images viewed by the two eyes, and the images can be analyzed to generate the three-dimensional vision in the viewer's brain. Stereoscopic imaging technique includes holographic images, grating images, lens images, and so on. A method of applying an optical grating structure to image the stereograph is easier than other methods, and is utilized widespread. Generally, there are two types of common methods for generating the stereograph. One conventional method is printing the images processed by stereographic image processing technique on a back of the optical grating structure directly. The other conventional method is printing the images processed by the stereographic image processing technique on a common print medium, and then gluing the optical grating structure on the common print medium. However, process of gluing the optical grating structure on the print medium is complicated, spends working hours, and needs numerous glue to fix the optical grating structure on the print medium. The conventional methods print the stereograph slowly and increase manufacturing cost. Thus, design of a stereograph printing mechanism capable of printing the stereograph rapidly and having low cost is an important issue in the printing industry.